These compounds are known per se (cf. in particular Nouveau Traite de Chimie Minerale by Paul PASCAL, published by Masson), and the majority are even commercially available products which may be used as starting materials for producing other salts by conventional processes, such as by more or less heavy neutralisation of the acid or double decomposition. Hypophosphorous acid and some of its salts are soluble in water, whilst other salts are insoluble in water.
Although certain organophosphorous compounds, especially phosphites, have been proposed as active fungicidal materials, the literature does not describe the fungicidal properties of hypophosphites.